Assessment of Agricultural Land-use/ Land-cover Change in the Diamphwe River Basin using Sentinel-2 Imageries

抄録

Land use and land cover (LU/LC) classification is an important aspect of research in various sectors of society. With technological advancements, LU/LC classification is a catalyst to achieve set goals, including the Malawi 2063 agenda. Diamphwe Basin, with over 90% farmers, is in central Malawi on vastly flat land, with a lot of potential in both commercial and subsistence agriculture production. Using the September 2017 and 2022 Sentinel-2 images, supervised classification and change detection were performed to track LU/LC changes using the maximum likelihood algorithm. The classes used for this classification were dense vegetation, wetland vegetation, agricultural land, settlement land, and bare land. The results showed that dense vegetation land increased by 10%, mostly converted from wetlands in forest reserves, and agricultural land decreased by 15.5%, of which a large proportion was converted to settlement land, thus increasing settlement land (urbanization) by 11.7%. The increased dense forest is expected to have a cooling effect and can increase baseflow to river discharge, whereas decreased agricultural land is expected to have a heating effect on the land mass. However, owing to the proximity to agricultural land, people in the basin experience more heating effects than cooling effects. Urbanization can create a ready market and can be leveraged to increase agricultural production through irrigation in the basin, as seen in the case of the Ganges River Basin. An increase in dense forest area could lead to an increase in river discharge owing to an increase in basin storage in the form of a baseflow increase. Since almost all human developments occur on land, LU/LC change detection is the key to policymakers and other stakeholders in achieving the three pillars of the Malawi 2063 agenda, thus agricultural development, industrialization, and urbanization by keeping abreast of the changes on the land.